Grinding wheel



A ril 10, 1934. c. H. SCHURR 1,954,330

GRINDING WHEEL Filed Aug. 15, 1930 l2 9 lo f: Z /6{ C lg VENTOR Patented Apr. 10, 1934 UNITED STATES GRINDING WHEEL Charles H. Schurr, Cleveland, Ohio, assignor to The Lees-Bradner Company, Cleveland, Ohio,

a corporation of Ohio Application August 15, 1930, Serial No. 475,427

2 Claims.

This invention relates to a grinding wheel. The wheel to which it relates is particularly adapted to the use in accurate grinding operations such as grinding the teeth of gears.

Heretofore, grinding Wheels for accurate work have been made of a single ring of vitrified material or the like containing abrasive, which ring is clamped between two generally circular plates mounted upon the spindle of a machine. These wheels have been provided with a flat surface normal to the axis of the spindle, and have been quite effective in doing accurate work, but have been expensive to manufacture, due to the relatively large diameter in proportion to their thickness, which necessitates the handling of the rings in small quantities, and the loss due to breakage and the like has been high.

It is an object of the present invention to produce an improved grinding wheel which will possess all the advantages in operation of the unitary type heretofore in use, while reducing the expense of manufacture and due to replacements.

Another object is to provide an improved grinding wheel in which a large proportion of the abrasive material may be utilized in grinding.

Other objects will hereinafter appear.

The invention will be better understood from the description of one practical embodiment thereof illustrated in the accompanying drawing, in which;

Figure 1 is a fragmentary side elevational view of one form of wheel embodying the invention;

Figure 2 is an axial cross-section thereof; and

Figure 3 is a fragmentary sectional view taken on the line III-III of Figure 2.

Two metal supporting discs 1 and 2 are arranged to be mounted upon and coaxial with the spindle 3 of a grinding machine. These wheels may be clamped together in any desired manner, conveniently by bolts 4. The inner edge at the peripheries of one of the wheels 1 is recessed to provide a shoulder 5, these parts being of wellknown construction and used to grip the grinding ring of prior construction within the recess in the "plates. In the drawing is illustrated a metal ring 6 which is gripped between the plates and seated in the recess, this ring having a radially extending flange 7, so that a cylindrical surface 8 is provided. The flange '7 is provided with spaced bosses 9 for a purpose to be hereinafter described.

first mentioned ring. Each inner surface 13 of the ring is of substantially frustro-conical shape, and between this and the fiat inner surface of the other ring may be clamped the dovetailedshaped inner edges 14 of a plurality of segments I of abrasive material.

These segments extend radially outward as indicated at 15, beyond the metal rings and then obliquely as indicated at 16, terminating in flat grinding surfaces 17 normal to the axis of the spindle.

The dovetail inner surface of each segment is gripped between the two pairs of bosses on the metal rings, and preferably between the abrasive material and metal some softer material, such as a blotting paper gasket 18 is inserted. Rubber spacers 19 are inserted between the ends of adjacent segments, which by their compression will allow for variations in the length of the segments.

Obviously the segments are much more convenient to handle in the processes to which they are subjected in their manufacture than are complete rings. Such breakage as does occur occasions the scrapping of relatively small parts, the replacement of which is much less expensive than the replacement of entire unitary rings.

The wheel may be repeatedly dressed in operation until it has been reduced to the size indicated by the dashed lines at A in Figure 2, showing that well over one-half the material may be utilized in productive work, and relatively little is wasted.

While I have described the illustrated embodiment of my invention in some particularity, this is done by way of illustration only, it being obvious that many other embodiments will readily occur to those skilled in this art, and I do not, therefore, limit myself to the precise details shown and described, but claim as my invention all embodiments, variations and modifications coming within the scope of the appended claims.

I claim:

1. A grinding wheel comprising a pair of rings enclosing between them an outwardly opening annular recess, the recess tapering in cross section and having its greatest width directed toward the axis of the rings, a plurality of segments of abrasive material, each having an inner section fitting within said recess and an outer section of generally hollow conical shape, the rings having corresponding pairs of projections extending into the recess whereby each segment of the abrasive material is gripped between one pair of projections adjacent each end.

having corresponding pairs of projections ex'-" tending into the recess whereby each segment of the abrasive material is gripped between onepair of projections adjacent each end, and gaskets interposed between said projections and said abrasive segments.

CHARLES H. SCHURR. 

